Working device and double-arm type working device

ABSTRACT

A working device has a configuration with seven degrees of freedom, and is configured to perform work using an end effector. The working device includes: a linear motion unit having three degrees of freedom; a rotary unit having three degrees of freedom; and a rotary drive mechanism having one degree of freedom. The rotary drive mechanism is configured to rotate the rotary unit relative to the linear motion unit. The linear motion unit is mounted on a mount such that a base portion thereof is fixed to the mount. The rotary drive mechanism is mounted on an output portion of the linear motion unit. The rotary unit is mounted on an output portion of the rotary drive mechanism. The end effector is mounted on an output portion of the rotary unit.

CROSS REFERENCE TO THE RELATED APPLICATION

This application is a continuation application, under 35 U.S.C. § 111(a)of international patent application No. PCT/JP2017/040331, filed Nov. 8,2017, which claims priority to Japanese patent application No.2016-220341, filed Nov. 11, 2016, the entire disclosure of which isherein incorporated by reference as a part of this application.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a working device and a double-arm typeworking device for use in equipment that requires high-speed andhigh-accuracy work such as medical equipment and industrial equipment,equipment that requires fine work such as assembly, a robot coexistingwith a person, etc.

Description of Related Art

Patent Documents 1 and 2, listed below, each propose an articulatedrobot type working device with six degrees of freedom. The workingdevice of Patent Document 1 has a single-arm configuration, and theworking device of Patent Document 2 has a double-arm type configuration.These working devices are each configured with six degrees of freedom asa whole by combining six mechanisms each having one rotational degree offreedom.

RELATED DOCUMENT Patent Document

[Patent Document 1] JP Laid-open Patent Publication No. 2005-329521

[Patent Document 2] JP Patent No. 4528312

SUMMARY OF THE INVENTION

The working device of Patent Document 1 is configured by a combinationof the mechanisms, all of which have one rotational degree of freedom,and thus has the following problems.

In the case of slightly changing the posture of an end effector mountedon a distal end or in the case of linearly moving such an end effector,it is necessary to drive a plurality of motors in a cooperative manner,and thus, it is impossible to perform fine work at a high speed.

Even in the case of slightly changing the posture of the end effector,not only a movement amount of a wrist joint (a joint near the endeffector) but also a movement amount of an arm (a part away from the endeffector) is increased. Therefore, a part of the working device islikely to come into contact with an object around the working device. Inorder to completely avoid such contact, it is necessary to provide alarge enclosure, and thus the occupation area becomes wide.

There are a plurality of paths for reaching one posture of the endeffector in some cases, and thus, it is hard to imagine in whichdirection the distal end of the end effector moves even when an arm ismoved about the rotation axis thereof when teaching. Therefore,knowledge and experience are needed to perform manipulations.

Since the range of movement is wide, it is necessary to assume cominginto contact with a person or an object and to enhance a contactprevention function, and therefore, the entire device becomes expensive.

In order to avoid contact with a person or an object, it is necessary toperform work at a reduced operation speed, or to perform work, at powerless than the ability, even in an operation range, and therefore, theability cannot be fully realized.

Even in the case where the contact prevention function is enhanced, anoperator minds coming into contact with the working device, andtherefore, it is difficult for a person and the working device tocoexist.

The working device of Patent Document 2 has the same problems as thoseof the working device of Patent Document 1. In addition, the workingdevice of Patent Document 2, which is of a double-arm type, has thefollowing problems.

Since the range of movement of each arm is wide, a region where the armsinterfere with each other is also wide. Knowledge and experience areneeded to perform operation such that the arms do not come into contactwith each other.

Since two arms having a wide range of movement are provided, theoccupation area becomes even wider when an enclosure is provided.

In order to solve the above problems, a working device has beensuggested in which the position and the angle of an end effector arechanged relative to a workpiece by a linear motion unit having threedegrees of freedom and a rotary unit having three degrees of freedom (JPLaid-open Patent Publication No. 2017-193009). With such a workingdevice as suggested, an operation amount of the entire device, whenperforming fine work, can be reduced, and the reliability of operationis high. Therefore, the working device can coexist with a person, andwork that is close to manual work performed by a person can beautomatically performed.

However, with such a working device as suggested, operation of the endeffector performed by moving the linear motion unit and the rotary unitcan be carried out only within a specific working space. The workingspace is a space that has a rectangular parallelepiped shape and isdefined by three linear motion actuators of the linear motion unit.Since the end effector can be operated only within the specific workingspace as described above, it is difficult to use the working device totransfer or deliver an article. In the case where it is necessary totransfer an article to a place around the working device or to bring inan article that is present around the working device, it is necessary toadditionally install a device for article transfer.

In addition, in the above suggested working device, the rotary unit isfixedly mounted on an output portion of the linear motion unit. Theabove suggested working device is also provided with a mechanism foradjusting the angle of the rotary unit relative to the linear motionunit, and this mechanism adjusts the angle of the rotary unit bychanging screw holes into which bolts for fixing the rotary unit to thelinear motion unit are to be screwed. Thus, the angle of the rotary unitcan be changed only to limited angles, and therefore, an optimum anglesuited for the content of work cannot be selected. Moreover, a pluralityof bolts are removed and attached when the angle is changed, andaccordingly, work for set-up change at the time of model change or thelike takes time and effort.

An object of the present invention is to provide a working device thatcan reduce an operation amount of the entire device when performing finework, has high reliability in operation, can coexist with a person, canautomatically perform work that is close to manual work performed by aperson, can deliver an article to a working device or an operatortherearound, and allows work for set-up change at the time of modelchange or the like to be easily performed thereon. Another object of thepresent invention is to provide a double-arm type working device thatcan perform work that is work performed by a person with both hands.

A working device of the present invention has seven degrees of freedomand is configured to perform work using an end effector, the workingdevice including: a linear motion unit having three degrees of freedomand obtained by combining three linear motion actuators; a rotary unithaving three degrees of freedom and obtained by combining a plurality ofrotating mechanisms each having one or more rotational degrees offreedom; and a rotary drive mechanism having one degree of freedom andconfigured to rotate the rotary unit relative to the linear motion unit,wherein the linear motion unit is mounted on a mount such that a baseportion thereof is fixed to the mount, the rotary drive mechanism ismounted on an output portion of the linear motion unit, the rotary unitis mounted on an output portion of the rotary drive mechanism, and theend effector is mounted on an output portion of the rotary unit.

According to this configuration, work is performed by the end effectoron a workpiece placed at a determined position. At this time, positionsof the end effectors are determined by the linear motion unit havingthree degrees of freedom, and a posture of the end effector isdetermined by the rotary unit having three degrees of freedom. Therespective linear motion actuators of the linear motion unit and therespective rotating mechanisms of the rotary unit respectivelycorrespond to the positions of the end effector represented in arectangular coordinate system and the posture of the end effectorrepresented in a polar coordinate system. Therefore, operations of therespective linear motion actuators and the respective rotatingmechanisms with respect to the position and the posture of each endeffector are easily imagined, and therefore, operation patterns forposture teaching work and the like are easily set. In addition,operating positions of the respective linear motion actuators andoperating angles of the respective rotating mechanisms are uniquelydetermined with respect to the position and the posture of each endeffector. That is, there is no singular point. Due to this, the workingdevice can be manipulated even without proficient knowledge andexperience.

By rotating the rotary unit relative to the linear motion unit by therotary drive mechanism, the end effector moves along a circulartrajectory. It is possible to carry out the above operation of the endeffector performed by moving the linear motion unit and the rotary unit,at an arbitrary position on the circular trajectory. Thus, by theworking device, not only work that is close to manual work performed bya person on a workpiece disposed at a determined position, but alsodelivery of an article to an operator or a working device around theworking device, can be performed. Accordingly, even when a conveyor lineis not provided, or when a minimum necessary transfer facility is merelyinstalled, a production line can be constructed.

Furthermore, when the rotary drive mechanism is provided, the angle ofthe rotary unit relative to the linear motion unit can be freely changedso as to be suited for the content of work. That is, the number of typesof work that can be performed by the one working device is increased ascompared to a working device that does not have the rotary drivemechanism. Since the angle of the rotary unit is easily changed, workfor set-up change that is performed when the model of the workpiece ischanged is made easier.

Additionally, the following operation and advantageous effects areachieved.

In the case of performing fine work such as assembling work, the workcan be performed mainly by moving only the rotary unit. Thus, since anoperation amount of the linear motion unit can be reduced, the range ofmovement of the entire device can be reduced, and the reliability ishigh. In addition, the area in which it is necessary to install aprotective measure such as an enclosure can be decreased.

Since the linear motion actuators are used in a portion that greatlyinfluences the range of movement, the operation range can be easilylimited by using a mechanical stopper, a limit sensor, or the like inaccordance with work contents or the ambient environment.

Since the linear motion unit and the rotary unit are separatelyprovided, it is possible to change only either unit in the case ofchanging the specifications of the working device. Accordingly,components can be shared by working devices having differentspecifications.

Since the positions of the end effectors are determined by the linearmotion actuators, linear motions of the end effectors can be accuratelymade at a high speed.

An enclosure such as a protective cover having a simple shape such as arectangular parallelepiped shape can be installed. In this case, thevolume of the internal space of the enclosure and the volume of theregion where movable portions move are substantially equal to eachother. Thus, a compact configuration can be achieved even when theprotection device is included.

In the present invention, at least one of the plurality of rotatingmechanisms of the rotary unit may be a link actuation device having twodegrees of freedom. The link actuation device may include: a proximalend side link hub and a distal end side link hub coupled to the proximalend side link hub via three or more link mechanisms such that a postureof the distal end side link hub can be changed relative to the proximalend side link hub, each link mechanism may include: a proximal side endlink member having one end rotatably coupled to the proximal end sidelink hub; a distal side end link member having one end rotatably coupledto the distal end side link hub; and an intermediate link member havingopposite ends rotatably coupled to other ends of the proximal side anddistal side end link members, respectively, and a posture controlactuator configured to arbitrarily change the posture of the distal endside link hub relative to the proximal end side link hub may be providedto each of two or more link mechanisms of the three or more linkmechanisms.

In the link actuation device, the proximal end side link hub, the distalend side link hub, and the three or more link mechanisms cooperatetogether to form a two-degrees-of-freedom mechanism in which the distalend side link hub is rotatable about two mutually orthogonal axesrelative to the proximal end side link hub. This two-degrees-of-freedommechanism is compact in size, but can achieve a wide range of movementfor the distal end side link hub. For example, the maximum value of abending angle between the central axis of the proximal end side link huband the central axis of the distal end side link hub is about ±90°, anda turning angle of the distal end side link hub relative to the proximalend side link hub can be set in the range of 0° to 360°. In addition, inthe operation range at a bending angle of 90° and a turning angle of360°, smooth operation can be performed without any singular point.

By using the link actuation device which can smoothly operate in a widerange of movement as described above, fine work can be performed at ahigh speed. In addition, the link actuation device has a compactconfiguration but has a wide range of movement, and thus, the entireconfiguration of the working device becomes compact.

When a point, at which a central axis of each of revolute pairs betweenthe proximal end side link hub and the proximal side end link membersand a central axis of each of revolute pairs between the proximal sideend link members and the intermediate link members intersect each other,is referred to as a proximal end side spherical link center, and astraight line, that passes through the proximal end side spherical linkcenter and intersects the central axis of each of the revolute pairsbetween the proximal end side link hub and the proximal side end linkmembers at a right angle, is referred to as a central axis of theproximal end side link hub, the two or more posture control actuators ofthe link actuation device may be rotary actuators and be disposed on acircumference of a virtual circle such that rotation output shafts ofthe rotary actuators are parallel to the central axis of the proximalend side link hub, rotational driving force of each rotation outputshaft may be transmitted to the link mechanism via an axis-orthogonaltype speed reducer, and another rotating mechanism for rotating the linkactuation device about the central axis of the proximal end side linkhub may be disposed at a center of arrangement of the respective posturecontrol actuators. In this case, the configuration of the rotary unitbecomes compact. In the present invention, each of the linear motionactuators of the linear motion unit may have a stage that is composed ofan advancing/retracting portion, and each of the stages may be disposedso as to be directed toward an outer side with respect to a workingspace in which work is performed by the respective end effectors. Whenthe stages of the respective linear motion actuators are disposed so asto be directed toward the outer side with respect to the working space,the working space can be wide, and also, the protection functionperformed when a hand is put into the working space is enhanced.

In the present invention, the three linear motion actuators of thelinear motion unit may include: a first linear motion actuatorconfigured to advance/retract in one direction along a horizontal plane;a second linear motion actuator configured to advance/retract along thehorizontal plane in a direction orthogonal to the one direction; and athird linear motion actuator configured to advance/retract in a verticaldirection, and the rotary drive mechanism may be disposed such that arotation axis thereof is parallel to an advancing/retracting directionof the first linear motion actuator or an advancing/retracting directionof the second linear motion actuator. According to this configuration,by rotating the rotary unit relative to the linear motion unit by therotary drive mechanism, a trajectory of movement of the end effector iseasily predicted in delivering an article to an operator or a workingdevice around the working device. Thus, the article can be assuredly andefficiently delivered.

A double-arm type working device of the present invention includes twoworking devices each of which is any of the working devices describedabove are aligned so as to be geometrically symmetrical with each other.When a double-arm type in which the two working devices are aligned isconfigured, it is possible to perform work that is performed with bothhands by a person. Accordingly, work that is performed as a substitutefor a person, in particular, work such as assembly of components, can beperformed.

Any combination of at least two constructions, disclosed in the appendedclaims and/or the specification and/or the accompanying drawings shouldbe construed as included within the scope of the present invention. Inparticular, any combination of two or more of the appended claims shouldbe equally construed as included within the scope of the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

In any event, the present invention will become more clearly understoodfrom the following description of preferred embodiments thereof, whentaken in conjunction with the accompanying drawings. However, theembodiments and the drawings are given only for the purpose ofillustration and explanation, and are not to be taken as limiting thescope of the present invention in any way whatsoever, which scope is tobe determined by the appended claims. In the accompanying drawings, likereference numerals are used to denote like parts throughout the severalviews, and:

FIG. 1 is a front view showing a schematic configuration of a workingdevice according to a first embodiment of the present invention;

FIG. 2A is a front view of a linear motion unit of the working device;

FIG. 2B is a plan view of the linear motion unit;

FIG. 3A is a front view of a rotary unit of the working device;

FIG. 3B is a plan view of the rotary unit;

FIG. 4 is a front view showing a schematic configuration of a workingdevice according to a second embodiment of the present invention;

FIG. 5A is a front view of the linear motion unit and a rotary drivemechanism of the working device;

FIG. 5B is a plan view of the linear motion unit and the rotary drivemechanism;

FIG. 6 is a front view showing a schematic configuration of a workingdevice according to a third embodiment of the present invention;

FIG. 7 is a front view representing a part of a rotary unit of theworking device in a cross-section;

FIG. 8 is a perspective view of a parallel link mechanism of a linkworking device of the rotary unit;

FIG. 9 is a perspective view of a different state of the parallel linkmechanism;

FIG. 10 is a cross-sectional view taken along a line X-X in FIG. 7;

FIG. 11 is a diagram representing one link mechanism of the linkactuation device with straight lines;

FIG. 12 is a front view of a different rotary unit;

FIG. 13 is a diagram showing a schematic configuration of a workingdevice according to a fourth embodiment of the present invention;

FIG. 14 is a front view of a main part of a rotary unit of the workingdevice;

FIG. 15 is a cross-sectional view taken along a line XV-XV in FIG. 14;

FIG. 16 is a front view of a main part of a different rotary unit;

FIG. 17 is a front view showing a schematic configuration of adouble-arm type working device according to a fifth embodiment of thepresent invention;

FIG. 18 is a perspective view of the double-arm type working device;

FIG. 19 is a plan view of linear motion units and rotary drivemechanisms of the double-arm type working device; and

FIG. 20 is a plan view of different linear motion units and rotary drivemechanisms.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present invention will be described withreference to the drawings.

First Embodiment

FIG. 1 to FIG. 3B show a working device according to a first embodimentof the present invention. As shown in a front view in FIG. 1 and in aplan view in FIG. 2B, the working device 1 includes: a mount 2; a linearmotion unit 3 that is mounted on the mount 2 such that a base portionthereof is fixed to the mount 2; a rotary drive mechanism 15 that ismounted on an output portion of the linear motion unit 3; a rotary unit4 that is mounted on an output portion of the rotary drive mechanism 15;and an end effector 5 that is mounted on an output portion of the rotaryunit 4.

The end effector 5 performs work on a workpiece 7 placed on a workpieceplacement table 6. The end effector 5 may perform work on the workpiece7 in a contact manner, or may perform work on the workpiece 7 in anon-contact manner. Work on the workpiece 7 by the end effector 5 isenabled within a working space S. The working space S is a space thathas a rectangular parallelepiped shape and is defined by later-describedthree linear motion actuators 11, 12, and 13 of the linear motion unit3.

The linear motion unit 3 has a configuration with three degrees offreedom in which three linear motion actuators are combined. The rotarydrive mechanism 15 has a configuration with one degree of freedom. Therotary unit 4 has a configuration with three degrees of freedom in whicha plurality of rotating mechanisms each having one or more rotationaldegrees of freedom are combined. Thus, the working device 1 has aconfiguration with seven degrees of freedom as a whole.

FIG. 2A is a front view of the linear motion unit 3, and FIG. 2B is aplan view of the linear motion unit 3. As shown in FIGS. 2A and 2B, thelinear motion unit 3 includes a first linear motion actuator 11, asecond linear motion actuator 12, and a third linear motion actuator 13.The first linear motion actuator 11 is mounted on a horizontal portion 2a of the mount 2, and includes a stage 11 a which advances/retracts inthe right-left direction (an X-axis direction). The second linear motionactuator 12 is mounted on the stage 11 a of the first linear motionactuator 11, and includes a stage 12 a which advances/retracts in thefront-rear direction (a Y-axis direction). The third linear motionactuator 13 is mounted on the stage 12 a of the second linear motionactuator 12, and a stage 13 a of the third linear motion actuator 13advances/retracts in the up-down direction or vertical direction (aZ-axis direction). The respective linear motion actuators 11, 12, and 13are electric actuators having motors 11 b, 12 b, and 13 b as drivesources. The respective linear motion actuators 11, 12, and 13 aredisposed such that the stages 11 a, 12 a and 13 a thereof are directedtoward the outer side with respect to the working space S.

In this embodiment, a portion, of the first linear motion actuator 11,that does not advance/retract corresponds to the “base portion of thelinear motion unit”, and this portion is fixed to the horizontal portion2 a of the mount 2. In addition, a connection fixing member 16 fixed tothe stage 13 a of the third linear motion actuator 13 corresponds to the“output portion of the linear motion unit”, and the rotary drivemechanism 15 is mounted on the connection fixing member 16. Theconnection fixing member 16 is fixed to the stage 13 a by means of bolts17 or the like.

A flat type motor such as a direct drive motor is used as the rotarydrive mechanism 15. In the case of this embodiment, a rotation axis O ofthe rotary drive mechanism 15 is parallel to the advancing/retractingdirection of the second linear motion actuator 12 of the linear motionunit 3 (a Y-axis direction). A base portion of the rotary unit 4 isfixed to a motor output shaft 15 a, which forms the output portion ofthe rotary drive mechanism 15, by means of bolts or the like (notshown).

FIG. 3A is a front view of the rotary unit 4, and FIG. 3B is a plan viewof the rotary unit 4. As shown in FIGS. 3A and 3B, the rotary unit 4includes: a rotary unit mounting member 20 that is fixed to the motoroutput shaft 15 a of the rotary drive mechanism 15 (see FIG. 1 and FIGS.2A and 2B); a first rotating mechanism 21 that is mounted on the rotaryunit mounting member 20; a second rotating mechanism 22 that is mountedon a rotating portion 21 a of the first rotating mechanism 21; and athird rotating mechanism 23 that is mounted on a rotating portion 22 aof the second rotating mechanism 22. The rotation axes 21 b, 22 b, and23 b of the first, second, third rotating mechanisms 21, 22, and 23 areorthogonal to each other. Rotational drive sources of the respectiverotating mechanisms 21, 22 and 23 are, for example, motors 21 c, 22 cand 23 c.

In this embodiment, the rotary unit mounting member 20 corresponds tothe “base portion of the rotary unit”, and is fixed to the motor outputshaft 15 a of the rotary drive mechanism 15. In addition, a rotatingportion 23 a of the third rotating mechanism 23 corresponds to the“output portion of the rotary unit”, and the end effector 5 is mountedon the rotating portion 23 a.

[Operation]

Operation of the working device 1 will be described. According to thisconfiguration, work is performed by the end effector 5 on the workpiece7 placed on the workpiece placement table 6 as shown in FIG. 1. At thistime, a position of the end effector 5 is determined mainly by thelinear motion unit 3 having three degrees of freedom, and a posture ofthe end effector 5 is determined by the rotary unit 4 having threedegrees of freedom. Operating positions of the respective linear motionactuators 11, 12 and 13 of the linear motion unit 3 correspond to theposition of the end effector 5 represented in a rectangular coordinatesystem, and operating positions of the respective rotating mechanisms21, 22 and 23 of the rotary unit 4 correspond to the posture of the endeffector 5 represented in a polar coordinate system. Thus, operations ofthe respective linear motion actuators 11, 12 and 13 and the respectiverotating mechanisms 21, 22, and 23 with respect to the position and theposture of the end effector 5 are easily imagined, and therefore,operation patterns for posture teaching work and the like are easilyset.

In addition, operating positions of the respective linear motionactuators 11, 12, and 13 and operating angles of the respective rotatingmechanisms 21, 22, and 23 are uniquely determined with respect to thepositions of the end effector 5 and the posture of the end effector 5B.That is, there is no singular point. Due to this, it is easily imaginedin which direction the distal end of the end effector 5 moves when anarm is moved about a rotation axis thereof during teaching. Therefore,the working device 1 can be manipulated even without proficientknowledge and experience.

In the case of performing fine work such as assembling work on theworkpiece 7 by using the end effector 5, the work can be performedmainly by moving only the rotary unit 4. Thus, since an operation amountof the linear motion unit 3 can be reduced, the range of movement of theentire device can be reduced, and the reliability is high.

Since the position of the end effector 5 are determined by the linearmotion actuators 11, 12 and 13, linear motion of the end effector 5 canbe accurately made at a high speed. In addition, since the linear motionactuators 11, 12, and 13 are used in a portion that greatly influencesthe range of movement, the operation range can be easily limited byusing a mechanical stopper, a limit sensor, or the like in accordancewith work contents or the ambient environment.

Since the respective linear motion actuators 11, 12, and 13 of thelinear motion unit 3 are disposed so as to be directed toward the outerside with respect to the working space S, the working space S can bewide. In addition, the protection function performed, for example, whena hand is put into the working space S, is enhanced.

Since the linear motion unit 3 and the rotary unit 4 are separatelyprovided, it is possible to change only either unit in the case ofchanging the specifications of the working device 1. For example, therotary unit 4 can be changed from the form shown in FIGS. 3A and 3B to aform shown in FIG. 7 described later, a form shown in FIG. 14 describedlater, a form shown in FIG. 16 described later, or the like.Accordingly, components can be shared by working devices 1 havingdifferent specifications.

By rotating the rotary unit 4 relative to the linear motion unit 3 bythe rotary drive mechanism 15, the end effector 5 moves along a circulartrajectory K (see FIG. 1) centered on the rotation axis O. It ispossible to carry out the above operation of the end effector 5performed by moving the linear motion unit 3 and the rotary unit 4, atan arbitrary position on the circular trajectory K. Thus, by the workingdevice 1, not only work that is close to manual work performed by aperson on a workpiece 7 disposed at a determined position, but alsodelivery of an article to an operator or a working device around theworking device 1, can be performed. Accordingly, even when a conveyorline is not provided, or when a minimum necessary transfer facility ismerely installed, a production line can be constructed.

For example, in the case of the working device 1 shown in FIG. 1, a toolcapable of holding an article is mounted as the end effector 5, anoperator waits near the right end of the circular trajectory K in FIG.1, and a position near the left end of the circular trajectory K is setas a position to which an article is delivered. The operator places anarticle on the workpiece placement table 6, the end effector 5 holds thearticle, and the rotary drive mechanism 15 is rotated leftward (in adirection in which the end effector 5 moves leftward), whereby thearticle is delivered from the right side to the left side in FIG. 1.Since the rotation axis O of the rotary drive mechanism 15 is directedin the front-rear direction (Y-axis direction), a trajectory of movementof the end effector 5 is easily predicted, and therefore, an article canbe assuredly and efficiently delivered.

In this embodiment, the rotation axis O of the rotary drive mechanism 15is parallel to the front-rear direction (Y-axis direction) that is theadvancing/retracting direction of the second linear motion actuator 12of the linear motion unit 3, but may be parallel to the right-leftdirection (X-axis direction) that is the advancing/retracting directionof the first linear motion actuator 11. In this case as well, atrajectory of movement of the end effector 5 is easily predicted, andtherefore, an article can be assuredly and efficiently delivered.

Furthermore, when the rotary drive mechanism 15 is provided, the angleof the rotary unit 4 relative to the linear motion unit 3 can be freelychanged so as to be suited for the content of work. That is, the numberof types of work that can be performed by the one working device 1 isincreased as compared to a working device that does not have the rotarydrive mechanism 15. Since the angle of the rotary unit 4 is easilychanged, work for set-up change that is performed when the model of theworkpiece 7 is changed is made easier.

As described above, when the working device 1 performs fine work, anoperation amount of the entire device is small. Thus, the reliability ofoperation is high, and the working device 1 can coexist with a person.That is, work that is close to manual work performed by a person can beautomatically performed. In addition, it is possible to shorten a set-upchange time and an adjustment time, high-speed operation can beperformed, an article can be delivered to an operator or a workingdevice around the working device 1, and work for set-up change at thetime of model change can be easily performed. Thus, productivity can beimproved.

Second Embodiment

FIG. 4 shows a working device that is different from that of the firstembodiment (see FIG. 1) in configuration of the rotary drive mechanism15. The rotary drive mechanism 15 of this working device 1 is composedof a flange output type motor. Similar to the above-mentioned firstembodiment, the rotary drive mechanism 15 is mounted on the connectionfixing member 16, which forms the output portion of the linear motionunit 3, such that the rotation axis O thereof is directed in thefront-rear direction. The output shaft of the rotary drive mechanism 15is a flange portion of the motor, and the rotary unit 4 is mounted onthe flange portion via a spacer member 15 b as shown in FIG. 5A and FIG.5B. In this case, the spacer member 15 b forms the output portion of therotary drive mechanism 15. The other configuration is the same as in thefirst embodiment.

Third Embodiment

FIG. 6 to FIG. 11 show a third embodiment of the present invention. Asshown in FIG. 6, in the working device 1, the rotary unit 4 includes afirst rotating mechanism 21 having one rotational degree of freedom, anda second rotating mechanism composed of a link actuation device 29having two rotational degrees of freedom. That is, the second rotatingmechanism 22 and the third rotating mechanism 23 in the first embodiment(see FIG. 1) are replaced with the link actuation device 29. The otherconfiguration is the same as in the first embodiment. In thisembodiment, the first rotating mechanism 21 corresponds to “anotherrotating mechanism” for rotating the link actuation device 29 about acentral axis of a proximal end side link hub.

As shown in FIG. 7, the link actuation device 29 includes a parallellink mechanism 30 and posture control actuators 31 that operate theparallel link mechanism 30. FIG. 8 and FIG. 9 are perspective views inwhich only the parallel link mechanism 30 is taken out and isrepresented, and show different states of the parallel link mechanism30. As shown in FIG. 7 to FIG. 9, the parallel link mechanism 30 isconfigured such that a distal end side link hub 33 is coupled to aproximal end side link hub 32 via three link mechanisms 34 such that theposture of the distal end side link hub 33 can be changed relative tothe proximal end side link hub 32. FIG. 7 shows only one link mechanism34. The number of link mechanisms 34 may be four or more.

Each link mechanism 34 includes a proximal side end link member 35, adistal side end link member 36, and an intermediate link member 37, andforms a quadric chain link mechanism composed of four revolute pairs.The proximal side and distal side end link members 35 and 36 each havean L-shape. The proximal side end link member 35 has one end rotatablycoupled to the proximal end side link hub 32, and the distal side endlink member 36 has one end rotatably coupled to the distal end side linkhub 33. The intermediate link member 37 has opposite ends rotatablycoupled to the other ends of the proximal side and distal side end linkmembers 35 and 36, respectively.

The parallel link mechanism 30 is formed by combining two spherical linkmechanisms, and the central axes of the revolute pairs between the linkhubs 32 and 33 and the end link members 35 and 36 and the central axesof the revolute pairs between the end link members 35 and 36 and theintermediate link members 37 intersect each other at spherical linkcenters PA and PB (FIG. 7) at the proximal end side and the distal side,respectively. In addition, at the proximal end side and the distal endside, the distances from the spherical link centers PA and PB to therevolute pairs between the link hubs 32 and 33 and the end link members35 and 36 are equal to each other, and the distances from the sphericallink centers PA and PB to the revolute pairs between the end linkmembers 35 and 36 and the intermediate link members 37 are also equal toeach other. The central axes of the revolute pairs between the end linkmembers 35 and 36 and the intermediate link member 37 may form a certaincross angle γ (FIG. 7), or may be parallel to each other.

FIG. 10 is a cross-sectional view taken along a line X-X in FIG. 7. FIG.8 shows a relationship between the central axes O1 of the revolute pairsbetween the proximal end side link hub 32 and the proximal side end linkmembers 35, the central axes O2 of the revolute pairs between theintermediate link members 37 and the proximal side end link members 35,and the proximal end side spherical link center PA. Specifically, thepoint at which the central axes O1 and the central axes O2 intersecteach other is the spherical link center PA. The shapes and thepositional relationship of the distal end side link hub 33 and thedistal side end link members 36 are the same as in FIG. 10 (not shown).In the shown example, the angle α formed by the central axis O1 of eachrevolute pair between the link hub 32 (33) and the end link member 35(36) and the central axis O2 of the revolute pair between the end linkmember 35 (36) and the intermediate link member 37 is set at 90°.However, the angle α may be an angle other than 90°.

The three link mechanisms 34 have a geometrically identicalconfiguration. The geometrically identical configuration means that, asshown in FIG. 11, a geometric model depicted with straight linesrepresenting the link members 35, 36, and 37, that is, a model depictedwith the revolute pairs and straight lines connecting these revolutepairs, represents a shape in which a proximal end side portion and adistal end side portion are symmetrical with each other with respect tothe center portion of the intermediate link member 37. FIG. 11 is adiagram representing one link mechanism 34 with straight lines. Theparallel link mechanism 30 of this embodiment is of a rotationsymmetrical type, and has a positional configuration in which thepositional relationship between a proximal side region, composed of theproximal end side link hub 32 and the proximal side end link member 35,and a distal side region, composed of the distal end side link hub 33and the distal side end link member 36, has rotation symmetry relativeto a center line C of the intermediate link member 37. The centerportion of each intermediate link member 37 is located on a commonorbital circle D.

The proximal end side link hub 32, the distal end side link hub 33, andthe three link mechanisms 34 cooperate together to form atwo-degrees-of-freedom mechanism in which the distal end side link hub33 is rotatable about two mutually orthogonal axes relative to theproximal end side link hub 32. In other words, thetwo-degrees-of-freedom mechanism allows the distal end side link hub 33to rotate with two degrees of freedom to change its posture, relative tothe proximal end side link hub 32. This two-degrees-of-freedom mechanismis compact in size, but can achieve a wide range of movement for thedistal end side link hub 33 relative to the proximal end side link hub32.

For example, when straight lines that pass through the spherical linkcenters PA and PB and intersect the central axes O1 (FIG. 10) of therespective revolute pairs between the link hubs 32 and 33 and the endlink members 35 and 36 at a right angle are defined as central axes QAand QB of the link hubs 32 and 33, the maximum value of a bending angleθ (FIG. 11) between the central axis QA of the proximal end side linkhub 32 and the central axis QB of the distal end side link hub 33 can beabout ±90°. A turning angle φ (FIG. 11) of the distal end side link hub33 relative to the proximal end side link hub 32 can be set in the rangeof 0° to 360°. The bending angle θ means a vertical angle formed whenthe central axis QB of the distal end side link hub 33 is inclinedrelative to the central axis QA of the proximal end side link hub 32.The turning angle φ means a horizontal angle formed when the centralaxis QB of the distal end side link hub 33 is inclined relative to thecentral axis QA of the proximal end side link hub 32.

The posture of the distal end side link hub 33 relative to the proximalend side link hub 32 is changed with the point of intersection O betweenthe central axis QA of the proximal end side link hub 32 and the centralaxis QB of the distal end side link hub 33 as a rotation center. FIG. 8shows a state where the central axis QA of the proximal end side linkhub 32 and the central axis QB of the distal end side link hub 33 are onthe same line. FIG. 9 shows a state where the central axis QB of thedistal end side link hub 33 forms a certain operating angle relative tothe central axis QA of the proximal end side link hub 32. Even when theposture is changed, the distance L (FIG. 11) between the proximal endside and distal end side spherical link centers PA and PB does notchange.

When each link mechanism 34 satisfies the following respectiveconditions 1 to 5, the proximal side region, composed of the proximalend side link hub 32 and the proximal side end link member 35, and thedistal side region, composed of the distal end side link hub 33 and thedistal side end link member 36, move simultaneously due to thegeometrical symmetry. Thus, when rotation is transmitted from theproximal end side to the distal end side, the parallel link mechanism 30serves as a constant velocity universal joint in which the proximal endside and the distal end side are rotated by the same angle and at equalspeeds.

Condition 1: The angles and the lengths of the central axes O1 of therevolute pairs between the link hubs 32 and 33 and the end link members35 and 36 in each link mechanism 34 are equal to each other.

Condition 2: The central axes O1 of the revolute pairs between the linkhubs 32 and 33 and the end link members 35 and 36 and the central axesO2 of the revolute pairs between the end link members 35 and 36 and theintermediate link member 37 intersect each other at the spherical linkcenters PA and PB at the proximal end side and the distal end side.

Condition 3: The geometrical shapes of the proximal side end link member35 and the distal side end link member 36 are the same.

Condition 4: The geometrical shapes of the proximal end side portion andthe distal end side portion of the intermediate link member 37 are thesame.

Condition 5: The angular positional relationships between theintermediate link member 37 and the end link members 35 and 36 withrespect to the symmetry plane of the intermediate link member 37 areidentical between the proximal end side and the distal end side.

As shown in FIG. 7 to FIG. 9, the proximal end side link hub 32 includesa proximal end member 40 and three rotation shaft coupling members 41provided so as to be integrated with the proximal end member 40. Asshown in FIG. 10, the proximal end member 40 has a circular through hole40 a defined in a center portion thereof, and the three rotation shaftcoupling members 41 are disposed equidistantly in the circumferentialdirection around the through hole 40 a. The center of the through hole40 a is located on the central axis QA (FIG. 7) of the proximal end sidelink hub 32. A rotation shaft 42 having an axis that intersects thecentral axis QA of the proximal end side link hub 32 is rotatablycoupled to each rotation shaft coupling member 41. One end of theproximal side end link member 35 is coupled to the rotation shaft 42.

As shown in FIG. 10, the rotation shaft 42 is rotatably supported by therotation shaft coupling member 41 via two bearings 43. Each bearing 43is a ball bearing such as a deep groove ball bearing and an angularcontact ball bearing. These bearings 43 are mounted in a radially innerhole 44 provided in the rotation shaft coupling member 41, in a state ofbeing fitted therein, and are fixed by a method such as press-fitting,adhesion, and crimping. The same also applies to the type of and amounting method for bearings provided to the other revolute pairsections.

The one end of the proximal side end link member 35 and a sector-shapedbevel gear 45 (described later) are connected to the rotation shaft 42so as to be rotatable integrally with the rotation shaft 42.Specifically, a cut portion 46 is formed at the one end of the proximalside end link member 35, and the rotation shaft coupling member 41 isdisposed between inner and outer rotation shaft support portions 47 and48 that form both side portions of the cut portion 46. The bevel gear 45is disposed in contact with the inner surface of the rotation shaftsupport portion 47 on the inner side thereof. The rotation shaft 42 isinserted into a through hole formed in the bevel gear 45, a through holeformed in the inner rotation shaft support portion 47, hollows of theinner rings of the bearings 43, and a through hole formed in the outerrotation shaft support portion 48, in this order, from the inner side.Then, the bevel gear 45, the inner and outer rotation shaft supportportions 47 and 48 and the inner rings of the bearings 43 are sandwichedto be held between a head portion 42 a of the rotation shaft 42 and anut 50 screwed onto a threaded portion 42 b of the rotation shaft 42, soas to be connected to each other. Spacers 51 and 52 are interposedbetween the inner and outer rotation shaft support portions 47 and 48and the bearings 43, and a preload is applied to the bearings 43 at thetime of screwing the nut 50.

A rotation shaft 55 is connected to the other end of the proximal sideend link member 35. The rotation shaft 55 is rotatably coupled to oneend of the intermediate link member 37 via two bearings 53.Specifically, a cut portion 56 is formed at the other end of theproximal side end link member 35, and the one end of the intermediatelink member 37 is disposed between inner and outer rotation shaftsupport portions 57 and 58 that form both side portions of the cutportion 56. The rotation shaft 55 is inserted into a through hole formedin the outer rotation shaft support portion 58, hollows of the innerrings of the bearings 53, and a through hole formed in the innerrotation shaft support portion 57, in this order, from the outer side.Then, the inner and outer rotation shaft support portions 57 and 58 andthe inner rings of the bearings 53 are sandwiched to be held between ahead portion 55 a of the rotation shaft 55 and a nut 60 screwed onto athreaded portion 55 b of the rotation shaft 55, so as to be connected toeach other. Spacers 61 and 62 are interposed between the inner and outerrotation shaft support portions 57 and 58 and the bearings 53, and apreload is applied to the bearings 53 at the time of screwing the nut60.

As shown in FIG. 8 and FIG. 9, the distal end side link hub 33 includesa distal end member 70 and three rotation shaft coupling members 71provided equidistantly in the circumferential direction on the innersurface of the distal end member 70. The center of the circle having thecircumference on which the respective rotation shaft coupling members 71are disposed is located on the central axis QB of the distal end sidelink hub 33. A rotation shaft 73 having an axis that intersects the linkhub central axis QB is rotatably coupled to each rotation shaft couplingmember 71. One end of the distal side end link member 36 is coupled tothe rotation shaft 73 defined at the distal end side link hub 33. Arotation shaft 75 is rotatably coupled to the other end of theintermediate link member 37 and is coupled to the other end of thedistal side end link member 36. Similar to the above rotation shafts 42and 55, the rotation shaft 73 defined at the distal end side link hub 33and the rotation shaft 75 defined at the intermediate link member 37 arerotatably coupled to the other ends of the rotation shaft couplingmember 71 and the intermediate link member 37, respectively, via twobearings (not shown).

As shown in FIG. 7, the proximal end member 40 is coupled to a basemember 80 via a plurality of shafts 81, whereby the parallel linkmechanism 30 is mounted on the first rotating mechanism 21. The centralaxis QA of the proximal end side link hub 32 and the rotation axis 21 bof the first rotating mechanism 21 are located on the same line. Thebase member 80 is fixed to the rotating portion 21 a of the firstrotating mechanism 21. A cover 82 is attached between the outercircumferential edge of the proximal end member 40 and the outercircumferential edge of the base member 80, and a shielded space 83shielded from the outside is formed between the proximal end member 40and the base member 80.

The posture control actuators 31, which operate the parallel linkmechanism 30, are disposed within the shielded space 83 and are mountedon the proximal end member 40. The number of the posture controlactuators 31 is three, which is equal to the number of the linkmechanisms 34. Each posture control actuator 31 is composed of a rotaryactuator such as a motor, and a bevel gear 76 mounted on a rotationoutput shaft 31 a of the posture control actuator 31 and theabove-described sector-shaped bevel gear 45 mounted on the rotationshaft 42 at the proximal end side link hub 32 are in mesh with eachother. The bevel gear 76 and the sector-shaped bevel gear 45 cooperatetogether to form an axis-orthogonal type speed reducer 77. Anaxis-orthogonal type speed reducer may be formed by using anothermechanism that is not a bevel gear (for example, a worm mechanism).

In this example, the posture control actuators 31, the number of whichis equal to that of the link mechanisms 34, are provided. However, whenthe posture control actuators 31 are provided to two of the three linkmechanisms 34, the posture of the distal end side link hub 33 relativeto the proximal end side link hub 32 can be determined.

The link actuation device 29 operates the parallel link mechanism 30 byrotationally driving each posture control actuator 31. Specifically,when each posture control actuator 31 is rotationally driven, therotation of the posture control actuator 31 is transmitted to therotation shaft 42 via the axis-orthogonal type speed reducer 77 whilereducing the speed of the rotation, and the angle of the proximal sideend link member 35 relative to the proximal end side link hub 32 ischanged. Accordingly, the position and the posture of the distal endside link hub 33 relative to the proximal end side link hub 32 aredetermined. Since the central axis QA of the proximal end side link hub32 and the rotation axis 21 b of the first rotating mechanism 21 arelocated on the same line, coordinate calculation is easy.

When the central axis QA of the proximal end side link hub 32 and therotation axis 21 b of the first rotating mechanism 21 are located on thesame line, the operator easily imagines operation of the working device1, and thus can easily manipulate the working device 1. For example,work can be performed, while the posture of the end effector 5 is beingchanged, by: fixing the positions of three degrees of freedom determinedby the linear motion unit 3; fixing the angles of two degrees of freedomof the angles out of the three degrees of freedom determined by therotary unit 4; and changing only the angle of the remaining one degreeof freedom (for example, an angle about the central axis QB of thedistal end side link hub 33).

As described above, the link actuation device 29 can smoothly operate ina wide range of movement. Thus, when the rotary unit 4 includes the linkactuation device 29, fine work can be performed at a high speed. Inaddition, the link actuation device 29 has a compact configuration buthas a wide range of movement, and thus, the entire configuration of theworking device 1 becomes compact.

When the first rotating mechanism 21 is disposed at the proximal endside of the link actuation device 29 and the end effector 5 is mountedon the distal end side link hub 33 as in this embodiment, a load on thelink actuation device 29 can be reduced, and therefore, the linkactuation device 29 can be made compact and can be reduced in weight.The parallel link mechanism 30 of the link actuation device 29 isconfigured as a constant velocity universal joint. Thus, by cooperativecontrol of the link actuation device 29 and the first rotating mechanism21, work can be easily performed, while the posture of the end effector5 is being changed, by changing only the angle of the distal end sidelink hub 33 about the central axis QB. However, it is necessary to takeinto consideration cables connected to each posture control actuator 31,and thus, the rotation angle is limited.

FIG. 12 shows a rotary unit 4 in which alignment of the first rotatingmechanism 21 and the link actuation device 29 is inverted from that inthe configuration in FIG. 7. In this case, the central axis QB of thedistal end side link hub 33 of the link actuation device 29 and therotation axis 21 b of the first rotating mechanism 21 are located on thesame line. The other configuration is the same as that in FIG. 7.

With the configuration of the rotary unit 4 shown in FIG. 10, it is easyto arrange cables connected to the posture control actuators 31, and therotation angle is less likely to be limited. On the other hand, there isa drawback that a load on the link actuation device 29 increases. Otherthan this, the same operation and advantageous effects as in theconfiguration in FIG. 7 are achieved.

Fourth Embodiment

FIG. 13 to FIG. 15 show a fourth embodiment of the present invention. Asshown in FIG. 13, in this working device 1 as well, similar to the thirdembodiment (see FIG. 6), the rotary unit 4 includes a first rotatingmechanism 21 that is a rotating mechanism having one degree of freedom,and a link actuation device 29 that is a rotating mechanism having twodegrees of freedom. The working device 1 of the fourth embodiment isdifferent from that of the third embodiment in that the first rotatingmechanism 21 is disposed at a center portion of the posture controlactuators 31 of the link actuation device 29.

As shown in FIG. 14, the first rotating mechanism 21 includes: a fixedportion 90 that is fixed to the base member 80; a rotating portion 91that is fixed to the proximal end member 40 of the link actuation device29; two bearings 92 via which the rotating portion 91 is rotatablysupported on the fixed portion 90; a motor 93 that is a drive sourcemounted on the fixed portion 90; and a pair of spur gears 94 and 95 thattransmit rotation of the motor 93 to the rotating portion 91.

The base member 80 is fixed to the rotary unit mounting member 20. Thefixed portion 90 includes: a first mounting member 96 that is fixed tothe base member 80 and has a cross-section with a horseshoe shape shownin FIG. 13; and a second mounting member 97 that has a bottom portion 97a fixed to the first mounting member 96 and a tubular portion 97 bextending from the outer circumferential edge of the bottom portion 97 ain the upward direction in FIG. 14. The rotating portion 91 is fixed tothe proximal end member 40 of the proximal end side link hub 32 suchthat the rotation axis 91 a of the rotating portion 91 is located so asto be coaxial with the central axis QA of the proximal end side link hub32. The two bearings 92 are disposed on the inner periphery of thetubular portion 97 b of the second mounting member 97.

The motor 93 is disposed in a recess 96 a of the first mounting member96 having a cross-section with a horseshoe shape, and is fixed to thebottom portion 97 a of the second mounting member 97. An output shaft 93a of the motor 93 extends upward, and penetrates the bottom portion 97 aof the second mounting member 97. The spur gear 94 at the drive side ismounted on the upper end of the output shaft 93 a. The spur gear 94 atthe drive side is in mesh with the spur gear 95 at the driven side whichis mounted on the rotating portion 91. The spur gear 95 at the drivenside is fitted on the outer periphery of the rotating portion 91 and isfixed to the rotating portion 91 by a nut 98 screwed on a threadedportion that is provided at the lower end of the rotating portion 91.

Wiring holes 100, 101 and 102 are provided in the bottom portion 97 a ofthe second mounting member 97, the rotating portion 91 and the proximalend member 40, respectively, so as to penetrate along the rotation axis91 a of the rotating portion 91. A cover 82 is attached to the outercircumferential edge of the proximal end member 40 so as to extend tothe vicinity of the outer circumferential edge of the base member 80.The cover 82 and the base member 80 are not connected to each other.

Similar to the configuration in FIG. 7, the three posture controlactuators 31 of the link actuation device 29 are disposed on thecircumference of a virtual circle on the proximal end member 40, androtational driving force of the rotation output shaft 31 a of eachposture control actuator 31 is transmitted via the axis-orthogonal typespeed reducer 77 to the link mechanism 34. In the case where the posturecontrol actuators 31 are disposed as described above, the first rotatingmechanism 21 can be disposed at the center of arrangement of the posturecontrol actuators 31 as in the third embodiment. Accordingly, theconfiguration of the rotary unit 4 becomes compact.

When the motor 93 is driven, the entire link actuation device 29 and thecover 82 rotate together with the rotating portion 91. By passing wiresthrough the wiring holes 100, 101, and 102, the wires can be connectedto the end effector 5 through the internal space of the link actuationdevice 29 without interference with the link mechanism 34. Thus,limitations on wires such as cables connected to the posture controlactuators 31 are reduced. The internal space of the link actuationdevice 29 refers to a space surrounded by the proximal end side link hub32, the distal end side link hub 33 and each link mechanism 34.

FIG. 16 is a front view of a main part of a different type rotary unit.In the rotary unit 4 shown in FIG. 14, the first rotating mechanism 21is disposed at a center portion of the respective posture controlactuators 31 of the link actuation device 29. This point is the same asin the configuration shown in FIG. 14, but the drive source of the firstrotating mechanism 21 shown in FIG. 14 is a hollow shaft motor 110unlike the configuration shown in FIG. 14.

The hollow shaft motor 110 includes: a motor body 110 a fixed to thebase member 80 via a motor mounting member 111; and an output shaft 110b to which the proximal end member 40 of the proximal end side link hub32 is fixed. The hollow shaft motor 110 has a wiring hole 112 thatpenetrates the motor body 110 a and the output shaft 110 b in the axialdirection thereof. In addition, a wiring hole 113 is also provided inthe proximal end member 40 of the proximal end side link hub 32 so as tobe coaxial with the wiring hole 112. The other configuration is the sameas the configuration shown in FIG. 14, and the same operation andadvantageous effects as in the configuration shown in FIG. 14 areachieved.

[Double-Arm Type Working Device]

FIG. 17 to FIG. 19 show a double-arm type working device according to afifth embodiment of the present invention. As shown in a front view inFIG. 17 and in a perspective view in FIG. 18, the double-arm typeworking device 120 includes two working devices 1, each of which is theworking device 1 of the fourth embodiment (see FIG. 13), are aligned soas to be geometrically symmetrical with each other. The mounts 2, 2 ofthe respective working devices 1, 1 are connected at tip ends of thehorizontal portions 2 a, 2 a thereof to each other to form a gate-shapedmount 2A as a whole. In the fifth embodiment, the working device 1 ofthe fourth embodiment is used, but the working device of anotherembodiment may be used.

When a double-arm type in which the two working devices 1 are aligned asdescribed above is configured, it is possible to perform work that isperformed with both hands by a person. Accordingly, work that isperformed as a substitute for a person, in particular, work such asassembly of components, can be performed. In addition, by making the endeffectors 5 of the respective working devices 1 close to each other bythe rotary drive mechanisms 15 as shown in FIG. 18, an article can bedelivered between the two working devices 1, 1.

Furthermore, when the two working devices 1, 1 are installed on thegate-shaped mount 2A, a workpiece 7 to be worked on can be passed belowthe working devices 1, 1. For example, a workpiece placement table 6 isconfigured as a conveyor device capable of conveying the workpiece 7 ina direction orthogonal to the sheet of FIG. 17, and the working devices1, 1 can be installed on a conveyor line of the conveyor device. Inaddition, the range of movement of the working devices 1, 1 in thewidthwise direction can be limited to a range within the width of themount 2A. Thus, the occupation area of the working devices 1, 1 can bereduced. Furthermore, since the range of movement of the working devices1, 1 is limited, an operator can perform work at ease even when beingpresent beside the working devices 1, 1.

FIG. 19 is a plan view of the linear motion units 3, 3 and the rotarydrive mechanisms 15, 15 of the double-arm type working device 120 shownin FIG. 17 and FIG. 18. In each linear motion unit 3, similar to thelinear motion unit 3 of each of the working devices 1 of the firstembodiment (see FIG. 1), the second embodiment (see FIG. 5), the thirdembodiment (see FIG. 6) and the fourth embodiment (see FIG. 13), therespective motors 11 b and 12 b of the first linear motion actuator 11and the second linear motion actuator 12 are disposed on the centralaxes of the linear motion actuators 11 and 12.

FIG. 20 is a plan view showing another form of the linear motion units3, 3 and the rotary drive mechanisms 15, 15. In each linear motion unit3, the respective motors 11 b and 12 b of the first linear motionactuator 11 and the second linear motion actuator 12 are disposed so asto be displaced from the central axes of the linear motion actuators 11and 12, and rotations of the motors 11 b and 12 b are transmitted todrive portions of the linear motion actuators 11 and 12 via powertransmission means 121 such as chains. Each linear motion unit 3 can bechanged to the form shown in FIG. 19 or the form shown in FIG. 20according to the specifications of the double-arm type working device120. Since the linear motion units 3 and the rotary units 4 areseparately provided, such form change is easy.

Although the present invention has been fully described in connectionwith the preferred embodiments thereof with reference to theaccompanying drawings which are used only for the purpose ofillustration, those skilled in the art will readily conceive numerouschanges and modifications within the framework of obviousness upon thereading of the specification herein presented of the present invention.Accordingly, such changes and modifications are, unless they depart fromthe scope of the present invention as delivered from the claims annexedhereto, to be construed as included therein.

REFERENCE NUMERALS

-   -   1 . . . working device    -   2 . . . mount    -   3 . . . linear motion unit    -   4 . . . rotary unit    -   5 . . . end effector    -   11 . . . first linear motion actuator    -   12 . . . second linear motion actuator    -   13 . . . third linear motion actuator    -   15 . . . rotary drive mechanism    -   15 a . . . motor output shaft (output portion of rotary drive        mechanism)    -   15 b . . . spacer member (output portion of rotary drive        mechanism)    -   16 . . . connection fixing member (output portion of linear        motion unit)    -   20 . . . rotary unit mounting member (base portion of rotary        unit)    -   21 . . . first rotating mechanism    -   22 . . . second rotating mechanism    -   23 . . . third rotating mechanism    -   23 a . . . rotating portion (output portion of rotary unit)    -   29 . . . link actuation device    -   31 . . . posture control actuator    -   32 . . . proximal end side link hub    -   33 . . . distal end side link hub    -   34 . . . link mechanism    -   35 . . . proximal side end link member    -   36 . . . distal side end link member    -   37 . . . intermediate link member    -   120 . . . double-arm type working device    -   O1 . . . central axis of revolute pair between link hub and end        link member    -   O2 . . . central axis of revolute pair between end link member        and intermediate link member    -   PA, PB . . . spherical link center    -   QA, QB . . . central axis of link hub    -   O . . . rotation axis    -   S . . . working space

What is claimed is:
 1. A working device having seven degrees of freedomand configured to perform work using an end effector, the working devicecomprising: a linear motion unit having three degrees of freedom andobtained by combining three linear motion actuators, wherein the threelinear motion actuators include: a first linear motion actuatorconfigured to advance and retract in a first direction along a firsthorizontal plane, a second linear motion actuator configured to advanceand retract along a second horizontal plane in a second directionorthogonal to the first direction, the second horizontal plane beingoffset from and parallel to the first horizontal plane, and a thirdlinear motion actuator configured to advance and retract in a verticaldirection; a rotary unit having three degrees of freedom and obtained bycombining a plurality of rotating mechanisms each having one or morerotational degrees of freedom; and a rotary drive mechanism having onedegree of freedom and configured to rotate the rotary unit relative tothe linear motion unit, wherein the linear motion unit is mounted on amount such that a base portion of the linear motion unit is fixed to themount, the rotary drive mechanism is mounted on an output portion of thethird linear motion actuator such that the rotary drive mechanism isspaced apart from the second linear motion actuator and is configured torotate the rotary unit about an axis parallel to the second direction,the rotary unit is mounted on an output portion of the rotary drivemechanism, and the end effector is mounted on an output portion of therotary unit, wherein at least one of the plurality of rotatingmechanisms of the rotary unit is a link actuation device having twodegrees of freedom, the link actuation device including: a proximal endside link hub, a distal end side link hub, three or more link mechanismsvia which the distal end side link hub is coupled to the proximal endside link hub such that a posture of the distal end side link hub can bechanged relative to the proximal end side link hub, each link mechanismincluding: a proximal side end link member having one end rotatablycoupled to the proximal end side link hub, a distal side end link memberhaving one end rotatably coupled to the distal end side link hub, and anintermediate link member having opposite ends rotatably coupled to otherends of the proximal side and distal side end link members,respectively, and a posture control actuator, configured to arbitrarilychange the posture of the distal end side link hub relative to theproximal end side link hub, provided to each of two or more linkmechanisms of the three or more link mechanisms, wherein a first cutportion is formed at the one end of the proximal side end link member,and a rotation shaft coupling member of the proximal end side link hubis disposed between inner and outer rotation shaft support portions thatform opposite side portions of the first cut portion, and a second cutportion is formed at the other end of the proximal side end link member,and one end of the intermediate link member is disposed between innerand outer rotation shaft support portions that form opposite sideportions of the second cut portion.
 2. The working device as claimed inclaim 1, wherein when a point, at which a central axis of each ofrevolute pairs between the proximal end side link hub and the proximalside end link members and a central axis of each of revolute pairsbetween the proximal side end link members and the intermediate linkmembers intersect each other, is referred to as a proximal end sidespherical link center, and a straight line, that passes through theproximal end side spherical link center and intersects the central axisof each of the revolute pairs between the proximal end side link hub andthe proximal side end link members at a right angle, is referred to as acentral axis of the proximal end side link hub, the two or more posturecontrol actuators of the link actuation device are rotary actuators andare disposed on a circumference of a virtual circle such that rotationoutput shafts of the rotary actuators are parallel to the central axisof the proximal end side link hub, rotational driving force of eachrotation output shaft is transmitted to the link mechanism via anaxis-orthogonal type speed reducer, and another rotating mechanism forrotating the link actuation device about the central axis of theproximal end side link hub is disposed at a center of arrangement of therespective posture control actuators.
 3. The working device as claimedin claim 1, wherein each of the first, second, and third linear motionactuators has a stage that is composed of an advancing and retractingportion, and each of the stages is disposed so as to be directed towardan outer side with respect to a working space in which work is performedby a respective end effector.
 4. A double-arm type working devicecomprising: two working devices, each of which is the working device asclaimed in claim 1, wherein the two working devices are aligned so as tobe geometrically symmetrical with each other.
 5. The working device asclaimed in claim 1, wherein the output portion of the rotary drivemechanism is a motor output shaft of the rotary drive mechanism, and arotational axis of the motor output shaft is spaced apart from andparallel to the second direction.
 6. The working device as claimed inclaim 1, wherein at least one of the plurality of rotating mechanisms ofthe rotary unit is a link actuation device having two degrees offreedom, the link actuation device including: a proximal end side linkhub connected to another rotating mechanism among the plurality ofrotating mechanisms of the rotary unit, a distal end side link hubcorresponding to the output portion of the rotary unit and to which theend effector is mounted on, and three or more link mechanisms via whichthe distal end side link hub is coupled to the proximal end side linkhub such that a posture of the distal end side link hub can be changedrelative to the proximal end side link hub.
 7. The working device asclaimed in claim 6, wherein the another rotating mechanism has onedegree of freedom and is to rotate the link actuation device about acentral axis of the proximal end side link hub, and the proximal endside link hub is connected to the another rotating mechanism via a basemember, wherein one end of the another rotating mechanism includes arotating portion which is fixed to the base member and another end ofthe another rotating mechanism is fixed to a base portion of the rotaryunit that is fixed to the output portion of the rotary drive mechanism.8. A working device having seven degrees of freedom and configured toperform work using an end effector, the working device comprising: alinear motion unit having three degrees of freedom and obtained bycombining three linear motion actuators; a rotary unit having threedegrees of freedom and obtained by combining a plurality of rotatingmechanisms each having one or more rotational degrees of freedom; and arotary drive mechanism having one degree of freedom and configured torotate the rotary unit relative to the linear motion unit, wherein thelinear motion unit is mounted on a mount such that a base portion of thelinear motion unit is fixed to the mount, the rotary drive mechanism ismounted on an output portion of the linear motion unit, the rotary unitis mounted on an output portion of the rotary drive mechanism, and theend effector is mounted on an output portion of the rotary unit, atleast one of the plurality of rotating mechanisms of the rotary unit isa link actuation device having two degrees of freedom, the linkactuation device including: a proximal end side link hub, a distal endside link hub, three or more link mechanisms via which the distal endside link hub is coupled to the proximal end side link hub such that aposture of the distal end side link hub can be changed relative to theproximal end side link hub, each link mechanism including: a proximalside end link member having one end rotatably coupled to the proximalend side link hub, a distal side end link member having one endrotatably coupled to the distal end side link hub, and an intermediatelink member having opposite ends rotatably coupled to other ends of theproximal side and distal side end link members, respectively, and aposture control actuator, configured to arbitrarily change the postureof the distal end side link hub relative to the proximal end side linkhub, provided to each of two or more link mechanisms of the three ormore link mechanisms, and wherein a first cut portion is formed at theone end of the proximal side end link member, and a rotation shaftcoupling member of the proximal end side link hub is disposed betweeninner and outer rotation shaft support portions that form opposite sideportions of the first cut portion, and a second cut portion is formed atthe other end of the proximal side end link member, and one end of theintermediate link member is disposed between inner and outer rotationshaft support portions that form opposite side portions of the secondcut portion.
 9. A working device having seven degrees of freedom andconfigured to perform work using an end effector, the working devicecomprising: a linear motion unit having three degrees of freedom andobtained by combining three linear motion actuators, wherein the threelinear motion actuators include: a first linear motion actuatorconfigured to advance and retract in a first direction along a firsthorizontal plane, a second linear motion actuator configured to advanceand retract along a second horizontal plane in a second directionorthogonal to the first direction, the second horizontal plane beingoffset from and parallel to the first horizontal plane, and a thirdlinear motion actuator configured to advance and retract in a verticaldirection; a rotary unit having three degrees of freedom and obtained bycombining a plurality of rotating mechanisms each having one or morerotational degrees of freedom; and a rotary drive mechanism having onedegree of freedom and configured to rotate the rotary unit relative tothe linear motion unit, wherein the linear motion unit is mounted on amount such that a base portion of the linear motion unit is fixed to themount, the rotary drive mechanism is mounted on an output portion of thethird linear motion actuator such that the rotary drive mechanism isspaced apart from the second linear motion actuator and is configured torotate the rotary unit about an axis parallel to the second direction,the rotary unit is mounted on an output portion of the rotary drivemechanism, and the end effector is mounted on an output portion of therotary unit, wherein the third linear motion actuator includes a stageconfigured to advance and retract in the vertical direction, the stageof the third linear motion actuator being disposed toward an outer sidewith respect to a working space in which work is performed by the endeffector mounted on the output portion of the rotary unit, the outputportion of the third linear motion actuator includes a connection fixingmember fixed to the stage of the third linear motion actuator, and therotary drive mechanism is mounted on the connection fixing member,wherein the output portion of the rotary drive mechanism includes amotor output shaft extending in the second direction, the rotary unitincludes a rotary unit mounting member fixed to the motor output shaft,and a first rotating mechanism among the plurality of rotatingmechanisms is mounted on the rotary unit mounting member.